The measure distance tool allows you to measure or validate the physical distance
between two points in a model.
On the 3D View
contextual tabs set, on the Mesh tab, in the
Tools group, click the Measure distance icon.
On the Tools tab, in the
Tools group, click the Measure distance icon.
Under Point1, use Ctrl+Shift+left click to snap to points (for example,
named points, geometry points, geometry face centre, geometry edge centre, mesh
vertices and grid).
The total distance, as well as the individual X axis, Y axis and Z axis distances, are displayed in the
Distance (D), X distance,
Y distance and Z distance
fields respectively.